This invention relates to a codeposition process for making hydrogen scavengers.
Hydrogen scavengers are useful when materials such as those in propellant systems or electronic components must be protected from the deleterious effects of exposure to hydrogen. There have previously been developed hydrogen scavengers which are a combination of an acetylenic organic material with a supported metal catalyst. Traditional preparation of such scavengers is accomplished by mixing a solid organic component with a solid metal catalyst in a ball mill process followed by grinding and pelletizing. The resulting scavenger material is typically placed into support tubes or other suitable containers. Such scavengers are useful as a bulk scavenger material when placed in proximity to an article to be protected from gaseous hydrogen. However, they do not ensure adequate protection of the article because they do not coat the article itself or otherwise act as a barrier between the article and hydrogen gas that may be present in the vicinity of the article.
Consequently, there is a need for hydrogen scavengers which can be deposited as coatings over large surface areas, onto complex shapes, or infiltrated into porous structures to function as both a scavenger and barrier.
It is therefore an object of this invention to provide hydrogen scavengers which can be applied to large, complex or porous surfaces and a simple, effective method of making the hydrogen scavengers.
It is another object of this invention to provide hydrogen scavengers which can be placed into proximity with the source of the hydrogen to be scavenged.
It is a further object of this invention to provide a codeposition process for making hydrogen scavengers.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. The claims appended hereto are intended to cover all changes and modifications within the spirit and scope thereof.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, there has been invented a codeposition process for fabricating hydrogen scavengers. First, a xcfx80-bonded allylic organometallic complex is prepared by reacting an allylic transition metal halide with an organic ligand complexed with an alkali metal; and then, in a second step, a vapor of the xcfx80-bonded allylic organometallic complex is combined with the vapor of an acetylenic compound, irradiated with UV light, and codeposited on a substrate. The invention process more particularly comprises:
1. combining an allylic transition metal halide with an anhydrous solvent to form a suspension;
2. combining said suspension with an alkali metal complexed with an organic ligand to obtain a reaction mixture having therein a xcfx80-bonded allylic organometallic complex and an alkaline earth halide;
3. isolating said xcfx80-bonded allylic organometallic complex from said reaction mixture;
4. vaporizing said xcfx80-bonded allylic organometallic complex to form a xcfx80-bonded allylic organometallic complex vapor;
5. vaporizing an acetylenic compound to form an acetylenic compound vapor;
6. combining said xcfx80-bonded allylic organometallic complex vapor with said acetylenic compound vapor to form a vapor mixture;
7. irradiating said vapor mixture with UV light energy to form a mixture of said acetylenic compound vapor and a disassociated xcfx80-bonded allylic organometallic complex vapor; and
8. allowing said mixture of said acetylenic compound vapor and said disassociated xcfx80-bonded allylic organometallic complex to condense upon a substrate.